Corrosion resistant compositions



United States Patent Ofl" 3,227,533 Patented Jan. 4, 1966 3,227,533CORROSION RESISTANT COMPOSITIONS Melvin E. Gililland, Port Arthur, andJames R. Zoller,

Groves, Tex., and Lawrence R. Burns, Brigham City,

Utah, assignors to Texaco line, New York, N.Y., a corporation ofDelaware No Drawing. Filed Aug. 31, 1961, Ser. No. 135,135

9 Claims. (Cl. 44-66) This invention relates to a corrosion inhibitorand corrosion inhibited fuel compositions. More particularly it relatesto a corrosion inhibitor composition and to petroleum distillate fuelshaving said composition incorporated therein which are haze resistant,essentially unreactive with water and of a low cloud point.

In coassigned, copending application Serial No. 860,- 114, filedDecember 17, 1959, now US. Patent No. 3,036,903, a paraifiniclubricating oil oxidate having a neutralization number (neut. No.)between about 55 and 80, a saponification number (sap. No.) betweenabout 100 and 200, an unsaponifiable content less than about 55 percent,a viscosity of less than 200 Saybolt Universal seconds (SUS) at 210 F.and a pour point less than 30 F. is taught as a corrosion inhibitor inpetroleum liquids such as the petroleum fuels, for example, gasoline,naphthas, kerosene and furnace oils. The preferred lube oil oxidates arelisted as having a neut. No. between 60 and 70, a sap. No. between 1 20and 165, an unsaponifiable content less than 55 percent, a viscosityless than 100 SUS at 210 F. and a pour point less than 10 F.

The source and manufacture of the aforedescribed lube oil oxidates aredescribed in coassign'ed US. Patent No. 2,978,472.

The lube oil oxidates, although liquid in nature, are very viscous andtherefore to facilitate their introduction into petroleum distillatefuel were diluted in the past with solvent such as a petroleum naphthahaving an API gravity of about 37", a flash point of about 160 F., aboiling range of about 370-550 F. and a 50 vol. percent A.S.T.M.distillation point of about 450 F., an aromatic content of above about14 wt. percent, and an olefin content of above about 1 wt. percent.Normally the lube oxida-tes comprised between about 50 and 90 wt.percent and the solvent comprises between about 10 and 50 wt. percent ofthe resultant corrosion inhibitor solution.

Although the aforedescribed lube oil oxidate and their solvent solutionswere effective corrosion inhibitors in petroleum distillate fuels, theydid have the disadvantage of reacting with any water contained in thefuel to form insoluble precipitates. Furthermore, the lube oil oxidatesand their previously described solvent solutions undesirably have beenfound to impart a haziness and a relatively high cloud point to thepetroleum distillates such as gasoline and jet fuels when incorporatedtherein.

The insoluble oxidate-water reaction solids are deleteriousin'distillate in that they collect in the screens, pumps and fuel linesof distillate fuel consuming engines thereby contributing to themalfunction thereof. Further the oxidate-water solid has a tendency toocclude water in a manner to prevent its ready removal. Water in jetfuels used in the operation of high altitude aircraft is particularlydisadvantageous. These fuels must be subtantially water-free otherwisethere is the constant hazard in high altitude flying of water collectingand freezing in the fuel lines, pumps and screens of the aircraftthereby resulting inflame-out of the jet engine. In addition to theforegoing a cloudy haze in a normally clear petroleum distillate fuelcreates considerable consumer resistance to the product whether or notit has actual detrimental efiect.

We have discovered a composition of a reduced cloud point that acts asan outstanding corrosion inhibitor in petroleum distillate fuels anddoes not form hazes or insoluble precipitates therein. Moreparticularly, these desirable properties are found in the inhibitorcombination comprising (1) the paratlinic lube oil oxidate as heretoforedescribed, (2) a polymerized fatty acid selected from the groupconsisting of dimers and trimers of ethylenic fatty acids of from 12 to22 carbon atoms and mixtures thereof, and (3) a paraffinic petroleumsolvent having an olefinic content between about 0 and 0.9 wt. percent,an aromatic content less than about 12 wt. percent, a boiling pointbetween about 300 and 650 R, an API gravity of between about 40 and anda viscosity (SUS) at 100 of between about 25 and 40. The solvent andpolym'erized fatty acid contemplated herein are believed to function incombination to repress the haze forming and water reaction tendency ofthe lube oil oxidate. In addi tion the polymerized fatty acidsurprisingly has been found to substantially reduce the cloud point ofsaid oxidate in fuels.

Desirable ingredient amounts in the foregoing oxidate composition isbetween about 30 and wt. percent oxidate, preferably between 40 and 60wt. percent, between about 1 and 10 wt. percent polymerized fatty acid,pref- 'erably between 3 and 7 wt. percent, and between about 25 and 70wt. percent petroleum parailinic solvent, preferably between 35 and 60wt. percent.

The amount of our inhibitor composition incorporated in petroleumdistillate fuels will vary depending on the corrosive conditionsencountered and the intended use of the fuel, however, for most purposesadvantageous amounts range from about 1 to about 100 pounds (lbs)inhibitor/thousand barrels (M bbls.) of distillate fuel. Typicalconcentrations that have been found useful in preventing rusting of ironsurfaces are from about 4 to 8 lbs. of inhibitor/ M bbls. of distillatefor pipeline protection and from about 10 to 30 lbs. of inhibitor/ Mbbls. of distillate for auto, aircraft and oil burner protection.

Examples of the distillate fuels contemplated herein are those petroleumdistillates having a boiling point range between about and 650 P. suchas gasoline, kerosene, jet fuels (JP4, JP-S), naphthas and furnace oils.

In respect to the polymerized fatty acid ingredients (dimers, trimersand mixtures thereof) contemplated herein their physical properties are.set forth in varying degrees in such U.S. Patents as 2,482,761 toGoebel, 2,631 ,979 to McDermott, and 2,632,695 to Landis et a1. It hasbeen shown that material consisting primarily of the dimer acid can beprepared by subjecting unsaturated fatty acids to moderate steampressures of from 80 to 300 p.s.i., at temperatures of from 260 to 360C. for a period of about 3 to 8 hours. 1

Another method for preparing the dimer acids broadly comprises heating ashort chain aliphatic alcohol ester of ethylenic fatty acid at about 300C. for several hours in an inert atmosphere. The resulting dimerizedester is then separated by distillation and hydrolyzed with hydrochloricacid or its equivalent. Fatty oils have also been heated to polymerizeand thereafter hydrolyzed to produce dimer acids. The first mentionedmethod of preparation is preferred however, owing to the fact that alarge percentage of dimer acids are produced from the starting materialsby the utilization of that method of production.

The trimer acid material is quite easily obtained. It can be separatedas it forms along with the monomers and higher polymer acids during thepreparation of dimer acids by the methods just described. In the case ofthe trimer acids, however, conventional methods for preparing polymeracids are preferred over the. method of Goebel, US. Patent No.2,482,761, wherein unsaturated acids are subjected to moderate steampressure, at moderate temperature for a few hours, since these othermethods produce high percentage of trimer acid material.

The mixture of dimer and trimer acids formed in these processes are attimes, for commercial reasons, separated from monomeric and higherpolymeric material present as well as from each other. However, thedimer and trimer acids can be employed in the invention compositionseither separately, mixed or with minor degrading amounts of monomer andhigher polymer acids.

The dimer and trimer acids and mixtures thereof of the ingredients ofthe present invention, although preferably conjugated products of twoand three of the same molecules which are the dior polyethylenic, arealso products of the combination of monoethylenic compounds andpolyetbylenic compounds. For instance, linoleic acid and oleic aciddimerize to become the dimer of linoleic and oleic acids. It is,however, necessary to have at least one polyethylenic compound presentto form the dimer and trimer.

The fatty acids useful in accordance with this invention includeethylenic, mono-carboxylic acids having from 12 to 22 carbon atoms,examples of which are as follows: 4-dodecenoic, 5,9-dimethyl-2,S-decadienoic, myristoleic, palmitoleic, oleic, linoleic,(9,1l-octadecadienoic, 10,12- octadecadienoic, 11,13-octadecadienoic)linolenic, erucic and 13,15-docosadienoic. The preferred acid islinoleic acid on the basis of availability, cost and function in thenovel compositions of the invention. Good source materials from whichthese fatty acids can be obtained by hydrolysis are vegetable oils, suchas soy bean oil, linseed oil, cotton seed oil, corn oil, castor oil,mustard seed oil and peanut oil.

Examples of the percentage composition of the polymerized fattymaterials consisting essentially of a dimer acid, trimer acid ormixtures thereof which are useful in accordance with the invention areas follows:

Wt. percent (1) Dimer acid 78 Trimer and higher polymer acids 22 (2)Dimer acid 72 Trimer and higher polymer acids 2O Monomer acid 8 (3)Dimer acid 85 Trimer and higher polymer acids l2 Monomer acid 3 (4)Dimer acid 92 Trimer and higher polymer acids 6 Monomer acids 1.5 Fattyresidue material 0.5

(5) Dimer acid 99.5 Fatty residue material 0.5

(6) Trimer acid 53 Dimer acid 35 Monomer acid 6 Higher polymer acid andfatty residue 6 (7) Trimer acid 85 Dimer acid 6 Higher polymer acid 5Monomer acid 4 (8) Trimer acid 65 Dimer acid 35 (9) Trimer acid 98 Fattyresidue 2 A preferred polymerized acid material consists of about 78 wt.percent of the dimer of linoleic acid and 22 wt. percent of the trimericand higher polymers of linoleic acid. This dimer acid material is alight colored 36 carbon unsaturated dibasic acid and has the followingproperties:

Acid value 185 Saponification number 190 Neut. equivalent 300 Color;(Gardner) 9 Viscosity at 25 C. (Gardner-Holdt) Z4 Flash point, F. 530

As previously stated the petroleum solvent ingredient is paratfinichydrocarbon petroleum distillate boiling in the range of between about300 and 650 F. More particularly it is further characterized by agravity between about 40 and 60 API, a viscosity (SUS) of between about25 and 40 at R, an aromatic content between about 0 and 12 wt. percentand an olefin content between 0 and 0.9 wt. percent with the remainderof the solvent being composed of normal and branch chain alkanes. Apreferred solvent has a boiling range between about 325 and 575 F., agravity of about 52 API, a viscosity (SUS) of about 32 at 100 R, anaromatic content of about 5 wt. percent and an olefin content of about 0wt. percent.

The inhibitor composition of the invention has the advantage of beingcompatible with many fuel additives whose particular function is notrelated to corrosion inhibiting. For example, in fuel oil distillateshaving a boiling point between about 300 and 650 F., sulfurized metalphenates, such as the CO neutralized sulfurized basic alkaline earthmetal alkyl (C to C phenolates, are often employed to prevent theformation of sludge. These phenates are described in US. Patent Nos.2,360,- 302, 2,362,291, 2,451,345 and 2,739,051. The inhibitorcomposition of the invention has been found to be particularly effectiveand compatible with the phenates in furnace oils in a weight ratio ofcorrosion inhibitor composition to phenate of between about 1:10 and10: 1. The total oxidate-phenate combination mixture is advantageouslypresent in furnace oils in an amount between about 5 and 100 lbs./ Mbbls. of furnace oil. A preferred phenate additive is a mixture of COneutralized sulfurized basic barium monoalkyl phenolates where theoverall barium content is between about 8 and 12 wt. percent and themonoalkyl group varies from 10 to 12 carbon atoms in chain length.

The following examples further illustrate the invention but are not tobe taken as limiting thereof:

sion inhibitor composition of the invention.

The ingredients employed in the procedure are as follows.

Parafiinic lube oil oxidate Characteristics:

Neut. No. 73 Saponification No. Unsaponifiable, wt. percent 40 Gravity,API 16 Viscosity, SUS

At 100 F. 1207 At 210 F. 78 Pour, F 0 Color, Lovibond A2 cell 60Polymerized acid Ingredients:

Dilinoleic acid, wt. percent 78 Trilinoleic acid and higher polylinoleicacid,

weight percent 22 Characteristics:

Neut. No 192 Sap. No 197 Unsaponifiable, wt. percent 0.36 Gravity, API15.9

iscosity, SUS

At 100 F 15,591 At 210 F 476 Pour, F. 5

Color, Lovibond /2" cell 40 Solvent Contents:

Olefins, wt. percent 0 Aromatics, wt. percent 8.9 Alkanes, wt. percent91.1

Characteristics:

Gravity, API 52.3 Flash, TCC, F 138 Refractive index 1.42912 Vol.percent distilled at F.

Initial B.P. 364

To a steel tank 41,916 lbs. of said paraflinic lube oil oxidate and41,916 lbs. of said solvent were added under mixing conditions. Theresultant mixture was passed to a settling tank where it was stored for60 hours at ambient temperature. At the end of the 60 hour period twolayers had formed with the bottom layer comprising an insolubleprecipitate and constituting 7 wt. percent of the tank contents. Theprecipitate was withdrawn and discarded. The upper layer was passedthrough a 130 ft. Dorr-Oliver precoat filter at 6.5 gal./hr./ft. and 100F. using a fine diatomaceous silica, as the precoat filter. To 31,060lbs. of the filtered oxidate solution there was added 1553 lbs. of saidpolymerized acid at ambient temperature and the resultant compositionwas mixed for a period of 7 hours by recirculating at a rate of 10bbls./hr. The final composition contained 44 wt. percent of saidoxidate, 51 wt. percent of said solvent and 5 wt. percent of saidpolymerized acid. Tests on the finished product found it to have a neut.No. of 32.0, a sap. No. of 57, and unsaponifiable content of wt.percent, an API gravity of 36, a flash point of 135 F., a viscosity(SUS) of 58.6 at 100 F. and 45.9 at 130 F., a Lovibond /2" cell colorrating of 10, a pour point of 50 F. and a cloud point of F.

EXAMPLE II This example illustrates the outstanding haze resistant andwater reaction resistant properties of the liquid oxidate compositionscontemplated herein.

5 Two compositions were subjected to the water-reaction test. The waterreaction test is described in U.S. Patent No. 2,978,472 and is a measureof the reactiveness of a distillate additive to water in a concentrationof 20 lbs. additive/M bbls. isooctane. Composition A is theoxidate-solvent-polymerized acid composition of the invention preparedin Example I. Composition B is identical to Composition A except thesolvent employed has a distillation range from 280 to 564 F., a vol.percent distillation point of 476 R, an aromatic content of 15.3 wt.percent, an olefinic content of 1.3 wt. percent and the remainder of thesolvent being composed of alkanes.

The following numerical ratings were used to evaluate the reactivity ofthe test compositions in the water reaction test, the higher the ratingthe greater the reactivity.

Rating: Appearance of the test sample 1 Clear and clean. 1b A fewbubbles around the periphery of the interface and no shreads of laceand/ or foam on the interface.

2 Shred of lace and/ or foam at the interface. 3 Lose lace and/or slightscum. 4 Light lace and/ or heavy scum.

It was found that Composition A gave the rating of 1 and Composition Bgave a rating of 2 thereby demonstrafing the necessity of thecombination of the particular polymerized acid and solvent contemplatedherein in order to prevent the reaction of the oxidate ingredient withwater to form undesirable solid and water occluding products.

The above water reaction test was conducted in aecordance with militaryspecification MIL-I-25017. In order for an additive to pass thismilitary specification in respect to jet fuels the rating should not begreater than 1b.

EXAMPLE III This example illustrates the haze resistant and low cloudproperties of the corrosion inhibitor combination.

Compositions A and B described in Example II and Composition C which isthe same as Composition A except the polymerized acid is omitted weredissolved in a JP-4 jet fuel in an amount corresponding to 20 lbs. ofcomposition/M bbls. fuel. The fuel containing Composition A, theinhibitor combination of the invention, was clear and had a cloud pointof 40 F. In contrast the JP-4 containing comparative Compositions B andC contained a significant haze and further the cloud point ofComposition C was found to be 65 F.

The foregoing cloud points were determined in accordance with ASTM TestD97.

EXAMPLE IV This example illustrates the corrosion inhibiting propertiesof the composition of the invention prepared in Example I.

The inhibitor of the invention was employed in a modified AST MCorrosion Test designated as D665 Procedure B. The ASTM Corrosion Testwas modified to the extent that the test temperature was F. and the'testduration was 20 hours. The following results were obtained.

Lbs. inhibitor/ M bbls, of isooctane: Percent rust EXAMPLE V Thisexample illustrates the compatibility of the petroleumoxidate-polymerized acid-solvent combination of the invention with otheradditives normally found in distillate fuels such as the metal phenatestabilizers.

The inhibitor composition prepared in Example I was combined with steamtreated, CO neutralized sulfurized barium monoalkyl (C to C phenolatecontaining 11.4 Wt. percent barium in a weight ratio of inhibitor tostabilizer of 1:3. Twenty (20) lbs. of this inhibitor-stabilizercombination were incorporated into a furnace oil having an API gravityof 35.5 a boiling range of between 370 and 631 F., and a 50 vol. percentdistillation point of 480 F. The resultant furnace oil mixture(Composition D) was subjected to a modification (3 hour test period at90 F. utilizing distilled water) of ASTM Corrosion Test D-665 and theAccelerated Stability Test. For comparison the fuel oil (Composition E)without the inhibitor and stabilizer was also tested.

The Accelerated Stability Test consists of heating 170 mls. of test oilfor 2 hours at a temperature of 275 F. while bubbling air through saidoil at the rate of 3 liters/hour. At the end of the 2 hour period thetest oil is cooled to room temperature within 1 hour and mls. of thecooled oil is vacuum filtered through a No. 1 Whatman filter paper. Arating of from 0 to '10 for the test oil is given depending on theamount of deposit from the oil remaining on the filter paper. A ratingof 0 indicates no deposit on the filter paper and therefore an oil ofhighest stability and a rating of 10 indicates the entire filter papercovered with a heavy black deposit and therefore an oil of loweststability.

The test results are reported below:

Corrosion test, percent rustfln Accelerated stability test,

filter doposit, rating I As can be seen from the above the compositionof the invention, Composition D, is non-corrosive and highly stable. Incomparison comparative Composition E is corrosive and unstable.

We claim:

1. A corrosion inhibitor composition for distillate fuels consistingessentially of (1) between about 30 and 70 wt. percent of a para'liiniclubricating oil liquid oxidate characterized by a neut. No. betweenabout 55 and 80, a sap. No. between about 100 and 200, an unsaponifiablecontent less than about 55 wt. percent, a pour point less than 30 F. anda viscosity less than 200 SUS at 210 F., (2) between about 1 and 10 wt.percent of a polymerized fatty acid consisting essentially of a memberselected from the group consisting of dimers and trimers of ethylenicfatty acid of from 12 to 22 carbons and mixtures thereof, and (3)between about 25 and 70 wt. percent a petroleum distillate solventhaving an API gravity between about 40 and 60, a boiling point between300 and 650 F., an aromatic content between about 0 and 12 wt. percentand an olefin content of about 0 wt. percent.

2. A composition in accordance with claim 1 wherein said polymerizedfatty acid consists essentially of the dimer and trimer of linoleic acidand said solvent has a boiling range between about 325 and 575 F., andan aromatic content of about 5 wt, percent.

3. A composition in accordance with claim 2 wherein said inhibitorcomposition comprises about 44 wt. percent of said oxidate, about 51 wt.percent of said solvent and about 5 wt. percent of said polymerizedfatty acid.

4. A liquid petroleum distillate fuel containing a rust inhibitingamount of a corrosion inhibitor composition, said composition consistingessentially of (1) between about 30 and 70 wt. percent of a parafiiniclubricating oil liquid oxidate characterized by a neut. No. betweenabout 55 and 80, a sap. No. between about 100 and 200, an unsaponifiablecontent less than about 55 wt. percent, a pour point less than 30 F. anda viscosity less than 200 SUS at 210 F., (2) between about 1 and wt.percent of a polymerized fatty acid consisting essentially of a compoundselected from the group consisting of dimers and trimers of ethylenicfatty acid of 12 to 22 carbons and mixtures thereof, and (3) betweenabout 25 and 70 Wt. percent of a petroleum distillate solvent having anAPI gravity between about 40 and 60, a boil ing point between 300 and650 R, an aromatic content between about 0 and 12 wt. percent and anolefin content of about 0 wt. percent.

5. A fuel in accordance with claim 4 wherein said rust 3 inhibitingamount is between about 1 and 100 lbs/M bbls. of said fuel.

6. A fuel in accordance with claim 5 wherein said polymerized fatty acidconsists essentially of the dimer and trimer of linoleic acid and saidsolvent has a boiling point range between about 325 and 575 F. and anaromatic content of about 5 wt. percent.

7. A fuel in accordance with claim 6 wherein said inhibitor compositioncomprises about 44 wt. percent of said oxidate, about 51 wt. percent ofsaid solvent and about 5 wt. percent of said polymerized fatty acid.

8. A furnace oil distillate having a boiling point between about 300 and650 F. containing an additive com bination in an amount between about 5and 100 lbs/M bbls. of said distillate, said combination consistingessentially of a stabilizer and corrosion inhibitor in a Weight ratio ofsaid stabilizer to said corrosion inhibitor of between about 1:10 and10:1, said stabilizer consisting essentially of a sulfurized metalphenate and said inhibitor consisting essentially of (1) between about30 and 70 wt. percent of a paraffinic lubricating oil liquid oxidatecharacterized by a neut. No. between about and 80, a sap. No. betweenabout 100 and 200, an unsaponifiable content less than about 55 wt.percent, a pour point less than 30 F. and a viscosity less than 200 SUSat 210 F., (2) between about 1 and 10 wt. percent of a polymerized fattyacid consisting essentially of a member selected from the groupconsisting of dimers and trimers of ethylenic fatty acid of from 12 to22 carbons and mixtures thereof, and (3) between about 25 and 70 wt.percent of a petroleum distillate solvent having an API gravity betweenabout 40 and a boiling point betveen 300 and 650 F., an aromatic contentbetween about 0 and 12 wt. percent and an olefin content of about 0 wt.percent.

9. A fuel oil in accordance with claim 8 wherein said weight ratio is 3:1, wherein said stabilizer is CO neutralized sulfurized barium monoalkylphenolate, wherein said polymerized fatty acid consists essentially ofdimer and trimer of linoleic acid and said solvent has a boiling rangebetween about 325 and 575 F, and an aromatic content of about 5 wt.percent.

References Cited by the Examiner UNITED STATES PATENTS 2,360,302 10/1944Etzler et al. 25232.5 2,632,695 3/1953 Landis et a1. 4466 2,739,0513/1956 Roger et al 4476 2,916,454 12/1959 Bradley et al 44-76 2,978,4724/1961 Kirkwood et al 252-55 DANIEL E. WYMAN, Primary Examiner.

4. A LIQUID PETROLEUM DISTILLATE FUEL CONTAINING A RUST INHIBITINGAMOUNT OF A CORROSION INHIBITOR COMPOSITION, SAID COMPOSITION CONSISTINGESSENTIALLY OF (1) BETWEEN ABOUT 30 AND 70 WT. PERCENT OF A PARAFFINICLUBRICATING OIL LIQUID OXIDATE CHARACTERIZED BY A NEUT. NO. BETWEENABOUT 55 AND 80, A SAP. NO. BETWEEN ABOUT 100 AND 200, AN UNSAPONIFIABLECONTENT LESS THAN ABOUT 55 WT. PERCENT, A POUR POINT LESS THAN 30*F. ANDA VISCOSITY LESS THAN 200 SUS AT 210*F., (2) BETWEEN ABOUT 1 AND 10 WT.PERCENT OF A POLYMERIZED FATTY ACID CONSISTING ESSENTIALLY OF A COMPOUNDSELECTED FROM THE GROUP CONSISTING OF DIMERS AND TRIMERS OF ETHYLENICFATTY ACID OF 12 TO 22 CARBONS AND MIXTURES THEREOF, AND (3) BETWEENABOUT 25 AND 70 WT. PERCENT OF A PETROLEUM DISTILLATE SOLVENT HAVING ANAPI GRAVITY BETWEEN ABOUT 40* AND 60*, A BOILING POINT BETWEEN 300 AND650*F., AN AROMATIC CONTENT BETWEEN ABOUT 0 AND 12 WT. PERCENT AND ANOLEFIN CONTENT OF ABOUT 0 WT. PERCENT.